Automatic book cutting-off device



Oct. 28, 1952 w LARK|N$ 2,615,410

AUTOMATIC BOOK CUTTING-OFF DEVICE Filed June 21, 1948 III I WLnz'fredAliarleins ATTD RNEYS Patented Oct. 28, 1952 UNITED STATES PATENT OFFICE -E i y 2,615,410

AUTOMATIC BOOK CUTTING-OFF DEVICE v Winifred A. Larkins, Kingsport, Tenn. Application June 21, 1948, Serial No. 34,318

I 1 V v This invention relates to machines for stitching together the folded edges of book signatures that are-successively fed to the stitching means but more particularly and specificallyit is directed to.- the. means with which the machine is provided-for severing the stitching threads between the last signature of one book and the first'signature of the following book.

'Ihe purposeof this invention is to improve book signature- -stitching machines by reciprocating the cutting knives instead of the pressureplates. I

. Primarily this invention has as an object the provision of new and useful improvements in the stitching thread severing means of a book stitchb l the thread cutting means of such book stitching machines which is accomplished in the present instance by a new and novel construction of the presser plates and of the thread cutting knives which operate in conjunction therewith.

7 Another important object of this invention resides in the provision of such thread severing means as have been set forth which are relatively inexpensive of design and manufacture and which may be easily installed to replace those.

cutting means now employed on such machines. Because the presser plates and the hook plates on'the'present machines are quite expensive, and

because the present construction of these parts permits them to be easily broken necessitating their replacement, this invention is highly desired and needed in the art.

Still further improvements and advantages of this'inv'ention will readily appear to those skilled inv the art when the following description is read in the lightof the accompanying drawings.

In the drawings:

. ..F'ig. 1 is a front elevation of a conventional. Estitching machine showing one relative position of the operable parts thereof.

Fig. 2 is a vertical section of the feeding saddle :and a needle, looper, and punch being shown in their relative positions thereto.

1 Claim. (Cl. 112-252) -2 Fig. 3 is a view looking upwardly toward the under surface of the cross bar of the machine showing an adjacent pair of the presser plates. Fig. 4 is a plan view of the unit shown in Fig. 3. Fig. 5' is a vertical section taken on line 5-5 of Fig. 3 with the machine cross bar omitted. Fig. 6 is an enlarged transverse section through a presser plate showing certain constructiona details thereof.

Fig. 7 is a view similar to Fig. 6 with the parts being shown in still another relationship.

Fig. 8 is a perspective .view showing in part a pair of book pads with the signature threads cut at their junction.

Referring now to the drawing wherein like reference characters denote corresponding parts the book signature cutting off device of this invention includes a plurality 'of pressure or throat plates.

The needles I and looper hooksZ are mountedally under the pressure plates to an assembled position'as illustrated in Figure 8.

' The pressure plates are formed with sections as indicated by the letter A the thickness of which is greater than that of the plates and the plates are'secured to the cross bar B of the ma chine by screws l2, which extend through these sections. 1

- The number of throat or pressure. plates used in these -machines depends uponthe sizes of the books to be stitched and the distance apart the lines of stitching are to be spaced. A single throat plate is illustrated herein as embodying the present invention and that shown is comprised of the body 3 which is designed to be secured to a supporting bar B, and members or knives 2| that are movably located in grooves 23 h in the under side of the body 3. The fixed mem-' f ber'3 is preferably fastened in'a mortise in the under face of the supporting bar by screw I 2 and the grooves are of such width that the members 21 may be shifted transversely. The fixed'member or pressure plate has openings l3 for the passage of the needle I and perforations l5 for may be made between the shifting bar and opcrating mechanism of the machine for reciprocating the bar and shifting the movable members with relation to the fixed members at the desired times. As an illustration the sliding bar 22 is connected at the point 32 to a lever 31 that is actuated by a cam 30.

L-shape knives or movable members also provide sections 21 that ride on the end surfaces of the sections A of the throat or pressure plates.

When a book is separated the ends 54, Fig. 8, of the cut tail stitch threads are drawn from the tail stitching through the loops of the chain stitching on the finished book, and then through the loops of the chain stitching on the first signature of the following book. After; one book is. stitched and before thejthreads are cut several signatures of the following book have been stitched so that in drawing out the threads the long ends of the threads remain in the loops of the chain and the books can be separated without loosening the stitching;

With the parts arranged in this manner the signatures are placed on the saddle 6 below the The needles and the hooks reciprocate as usual always in the same paths. As the signatures are being stitched the needles I which form the straight-line or'tail stitches pass through needle openings Ml in the slot 13 in the fixed members of the throat plates and also through one of the openingsv between the knives of themovable plates, while the hooks 2 which form thechain or headf-stitches'pass through hook perforations l5 inthe fixed members only. On the start the movable members or knives are in such position that the needles draw the threads throughthe openings I! in the movable members. After the last. signature of a book is stitched the connecting bar is moved so as to shift'the movable members sidewise and then while the needlespass through the same opening in the fixed member they Pass'through the openings [3 in the movable members. This causesloops of the thread to be. Wound around the sections I9 that are between the openings through the movable members as shown at the top of Fig. 3. After the lastsignature of each book is stitched the mov able members are shifted so as to loop'the tail stitch threads, that is, the movable members are moved to: one side and then back to the other side.

i As the: needles I form the tail stitches through the openings I! and iii, the looper 2 carries the looper thread 53 through the opening l5 and the sliding movement of the looper hook or knife 25 causes the thread to wrap around the knife 25,v as shown in Figure 3, at the same time the thread of the tail'stitch is wrapped around the section l9, Whereas, in the return movement in which the tail stitch is formed the thread of the double loop is looped to form the looper stitch. The knife 25 is provided with projections 26. on the, sides of the end to retain the thread thereon. The stitching continues and after several signatures have been stitched the backward movement of the stitched signatures causes the threaded loops to be drawn across the knife edges of the openings through the movable members andbe severed. At the same time the looper thread is drawn across the knife edge on the inner edgeof the looper. knife 25 whereby the looper thread is also out. such times that the threads are out between the last signature of one book and the first signature of the following book, but not until several following signatures have been stitched, so thatthe drawing of the threads does not loosen the stitching), in fact, it tightens the stitching.

By the combination of the looper thread knife or; hook 25 the chain or head'stitch is formed and cut, simultaneously with the tail stitch. The

This is effected atpressure or throat plates and the single thread needles I which form the tail stitches are reciprocated through the needle openings M in the plates to form a single threa'd,;as indicated by the numeral 5!, in holes that have been previously formed in the signature by punches 5, and at the same time the hook needles 2' are similarly reciprocated to form the loop-or double threads, as indicated by the numerals-'53' through similar holes in the signature. v I

What is claimed is:- I

In-a signature stitching machine, the combination which comprises a pressure plate for use on a book signature stitching machine, said pres sure plate having a slot with an enlarged needleopening in each end and also at a point midway between the ends, and also having a. looper hook opening therein aligned withthe needle openings of said slot, an L-shaped movable mem her having openings with knife edges positioned to register with" the enlarged needle openings of the slot slidably mounted on theunder surface of the pressure plate, said movable member also having a looperknife at the end of the section thereof in which the openings positioned to register with the needle openings of the slot arepositioned, a horizontally movable carrier secured. to said L-shaped movable member, said carrier positioned to be actuated by the stitching. ma.- chine whereby the movable member moves at in tervals transversely across the needle'path in a plane parallel with the line between thelneedl'e opening and hook opening and, dwells on one.

when the following book signatures, are being stitched, whereby at the finish of the. stitching] of the signatures of each book the needleand. looper. threads will be looped. oversaid section,

and looper knife and after the feed of several.

following signatures will be drawn around said section and looper knife to tighten the stitches and be severed.

REFERENCES CITED The followingreferences file of this patent:

UNITED STATES PATENTS v Number Name Date,

1,915,551 I Schramm June 27,1933, 2,021,669 Muller Nov. 19,1935. I FQREIGN PATENTS Number Country Date r 642,999 Germany Mai'Q22; 1937 WINIFRED are of record in; the. 

